using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net.Sockets;
using System.Threading; 
using System.Net;
using System.Runtime.InteropServices;
using System.IO;
using pb = Google.Protobuf;


/// <summary>
/// socket 辅助类
/// </summary>
public static class SocketUtils
{
    #region Socket
    /// <summary>
    /// socket辅助方法
    /// </summary>
    /// <param name="sock"></param>
    /// <param name="interval_ms"></param>
    public static void SetKeepAlive(this Socket sock, int interval_ms)
    {
        uint dummy = 0;
        byte[] inOptionValues = new byte[Marshal.SizeOf(dummy) * 3];
        BitConverter.GetBytes((uint)1).CopyTo(inOptionValues, 0);
        BitConverter.GetBytes((uint)interval_ms).CopyTo(inOptionValues, Marshal.SizeOf(dummy));
        BitConverter.GetBytes((uint)interval_ms).CopyTo(inOptionValues, Marshal.SizeOf(dummy) * 2);
        sock.IOControl(IOControlCode.KeepAliveValues, inOptionValues, null);
    }

    public static bool IsWriteAble(this Socket socket)
    {
        try
        {
            if (socket.Poll(-1, SelectMode.SelectWrite))
            {
                return true;
            }
        }
        catch (SocketException se)
        {
            System.Diagnostics.Debug.WriteLine(se.Message);
            return false;
        }
        return false;

    }
    public static bool IsReadAble(this Socket socket)
    {
        try
        {
            if (socket.Poll(-1, SelectMode.SelectRead))
            {
                return true;
            }
        }
        catch (SocketException se)
        {
            System.Diagnostics.Debug.WriteLine(se.Message);
            return false;
        }
        return false;
    }
    #endregion

    /// <summary>
    /// Task辅助方法
    /// </summary>
    /// <param name="task"></param>
    /// <param name="timeout"></param>
    /// <returns></returns>
    public static async Task WaitAsync(this Task task, TimeSpan timeout)
    {
        using (var timeoutCancellationTokenSource = new CancellationTokenSource())
        {
            var delayTask = Task.Delay(timeout, timeoutCancellationTokenSource.Token);
            if (await Task.WhenAny(task, delayTask) == task)
            {
                timeoutCancellationTokenSource.Cancel();
                return;
            }
            throw new TimeoutException("The operation has timed out.");
        }
    }

    /// <summary>
    /// ProtoBuf序列化
    /// </summary>
    /// <param name="data"></param>
    /// <returns></returns>
    public static byte[] ToBytes(this pb::IMessage data)
    {
        using var ms = new MemoryStream();
        using var os = new pb::CodedOutputStream(ms);
        data.WriteTo(os);
        os.Flush();
        ms.Seek(0, SeekOrigin.Begin);
        return ms.ToArray();
    }
}